The human-nonhuman animal boundary marks the interchange between human and animal, culture and nature, the social and the natural. This powerfully symbolic site has traditionally been structured via religion-based ideas of humanity's origins, that in the West have been used to maintain a strictly impermeable boundary: humans, created in God's own image and blessed with a soul on one side, on the other the senseless, soulless beast. This image is one which has come under threat from work in multiples branches of the natural and social sciences; in the humanities; and from animal rights activists and other social movements. Such culturally contested territory makes fertile ground for the study of interactions between science and popular culture, framed via Gieryn’s concept of 'boundary-work' (1983), and Bowker & Star’s sociology of classification (2000). Using the fossilised figures of palaeoanthropological research as a prominent site at which the aforementioned boundary is constructed, the thesis considers both how such “missing links” are positioned within the popular human-nonhuman animal dichotomy, and how the boundaries between science and nonscience culture are negotiated during this process. The project makes use of two case studies - the infamous Piltdown Man (discovered 1912) and the recent Flores ‘hobbit’ (2004). Both received huge scientific and popular attention at the time of their respective discoveries, and it is a critical discourse analysis of relevant scientific and popular news media that provides the research data. The thesis addresses how missing links create connections far beyond simply their antecedents and descendants. Indeed, their emblematic position sees them use to explore fundamental notions of humanness, becoming tied to all manner of socio-political ideologies in the process. It is through this process that their ‘natural’ position is made culturally meaningful. Such actions requires repeated transgression of the science-nonscience boundary, a lesson which is used to critique ‘canonical’ and ‘continuum’ models of science communication, and to suggest a more complex, multi-directional ‘hydrological’ model in their place. The thesis concludes by drawing attention to the gaps between formally recognised categories, and how these are utilised by scientists and journalists alike, both in the translation of these missing links between different systems of meaning, and in their role as a creative space for all parties to think with.